src/Network/native_fdm.cxx

   1 // native_fdm.cxx -- FGFS "Native" flight dynamics protocal class
   2 //
   3 // Written by Curtis Olson, started September 2001.
   4 //
   5 // Copyright (C) 2001  Curtis L. Olson - curt@flightgear.org
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License as
   9 // published by the Free Software Foundation; either version 2 of the
  10 // License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 // General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 //
  21 // $Id$
  22
  23
  24 #ifdef HAVE_CONFIG_H
  25 #  include <config.h>
  26 #endif
  27
  28 #include <simgear/debug/logstream.hxx>
  29 #include <simgear/io/lowlevel.hxx> // endian tests
  30 #include <simgear/io/iochannel.hxx>
  31 #include <simgear/timing/sg_time.hxx>
  32
  33 #include <FDM/flight.hxx>
  34 #include <Time/tmp.hxx>
  35 #include <Main/fg_props.hxx>
  36 #include <Main/globals.hxx>
  37 #include <Scenery/scenery.hxx>
  38
  39 #include "native_fdm.hxx"
  40
  41 // FreeBSD works better with this included last ... (?)
  42 #if defined(WIN32) && !defined(__CYGWIN__)
  43 #  include <windows.h>
  44 #else
  45 #  include <netinet/in.h>       // htonl() ntohl()
  46 #endif
  47
  48
  49 // The function htond is defined this way due to the way some
  50 // processors and OSes treat floating point values.  Some will raise
  51 // an exception whenever a "bad" floating point value is loaded into a
  52 // floating point register.  Solaris is notorious for this, but then
  53 // so is LynxOS on the PowerPC.  By translating the data in place,
  54 // there is no need to load a FP register with the "corruped" floating
  55 // point value.  By doing the BIG_ENDIAN test, I can optimize the
  56 // routine for big-endian processors so it can be as efficient as
  57 // possible
  58 static void htond (double &x)
  59 {
  60     if ( sgIsLittleEndian() ) {
  61         int    *Double_Overlay;
  62         int     Holding_Buffer;
  63
  64         Double_Overlay = (int *) &x;
  65         Holding_Buffer = Double_Overlay [0];
  66
  67         Double_Overlay [0] = htonl (Double_Overlay [1]);
  68         Double_Overlay [1] = htonl (Holding_Buffer);
  69     } else {
  70         return;
  71     }
  72 }
  73
  74 // Float version
  75 static void htonf (float &x)
  76 {
  77     if ( sgIsLittleEndian() ) {
  78         int    *Float_Overlay;
  79         int     Holding_Buffer;
  80
  81         Float_Overlay = (int *) &x;
  82         Holding_Buffer = Float_Overlay [0];
  83
  84         Float_Overlay [0] = htonl (Holding_Buffer);
  85     } else {
  86         return;
  87     }
  88 }
  89
  90
  91 FGNativeFDM::FGNativeFDM() {
  92 }
  93
  94 FGNativeFDM::~FGNativeFDM() {
  95 }
  96
  97
  98 // open hailing frequencies
  99 bool FGNativeFDM::open() {
 100     if ( is_enabled() ) {
 101         SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
 102                 << "is already in use, ignoring" );
 103         return false;
 104     }
 105
 106     SGIOChannel *io = get_io_channel();
 107
 108     if ( ! io->open( get_direction() ) ) {
 109         SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
 110         return false;
 111     }
 112
 113     set_enabled( true );
 114
 115     // Is this really needed here ????
 116     cur_fdm_state->_set_Sea_level_radius( SG_EQUATORIAL_RADIUS_FT );
 117
 118     return true;
 119 }
 120
 121
 122 void FGProps2NetFDM( FGNetFDM *net, bool net_byte_order ) {
 123     int i;
 124
 125     // Version sanity checking
 126     net->version = FG_NET_FDM_VERSION;
 127
 128     // Aero parameters
 129     net->longitude = cur_fdm_state->get_Longitude();
 130     net->latitude = cur_fdm_state->get_Latitude();
 131     net->altitude = cur_fdm_state->get_Altitude() * SG_FEET_TO_METER;
 132     net->agl = cur_fdm_state->get_Altitude_AGL() * SG_FEET_TO_METER;
 133     net->phi = cur_fdm_state->get_Phi();
 134     net->theta = cur_fdm_state->get_Theta();
 135     net->psi = cur_fdm_state->get_Psi();
 136     net->alpha = cur_fdm_state->get_Alpha();
 137     net->beta = cur_fdm_state->get_Beta();
 138     net->phidot = cur_fdm_state->get_Phi_dot_degps() * SG_DEGREES_TO_RADIANS;
 139     net->thetadot = cur_fdm_state->get_Theta_dot_degps()
 140         * SG_DEGREES_TO_RADIANS;
 141     net->psidot = cur_fdm_state->get_Psi_dot_degps() * SG_DEGREES_TO_RADIANS;
 142
 143     net->vcas = cur_fdm_state->get_V_calibrated_kts();
 144     net->climb_rate = cur_fdm_state->get_Climb_Rate();
 145
 146     net->v_north = cur_fdm_state->get_V_north();
 147     net->v_east = cur_fdm_state->get_V_east();
 148     net->v_down = cur_fdm_state->get_V_down();
 149     net->v_wind_body_north = cur_fdm_state->get_uBody();
 150     net->v_wind_body_east = cur_fdm_state->get_vBody();
 151     net->v_wind_body_down = cur_fdm_state->get_wBody();
 152
 153     net->A_X_pilot = cur_fdm_state->get_A_X_pilot();
 154     net->A_Y_pilot = cur_fdm_state->get_A_Y_pilot();
 155     net->A_Z_pilot = cur_fdm_state->get_A_Z_pilot();
 156
 157     net->stall_warning = fgGetDouble("/sim/alarms/stall-warning", 0.0);
 158     net->slip_deg
 159       = fgGetDouble("/instrumentation/slip-skid-ball/indicated-slip-skid");
 160
 161     // Engine parameters
 162     net->num_engines = FGNetFDM::FG_MAX_ENGINES;
 163     for ( i = 0; i < net->num_engines; ++i ) {
 164         SGPropertyNode *node = fgGetNode("engines/engine", i, true);
 165         if ( node->getBoolValue( "running" ) ) {
 166             net->eng_state[0] = 2;
 167         } else if ( node->getBoolValue( "cranking" ) ) {
 168             net->eng_state[0] = 1;
 169         } else {
 170             net->eng_state[0] = 0;
 171         }
 172         net->rpm[i] = node->getDoubleValue( "rpm" );
 173         net->fuel_flow[i] = node->getDoubleValue( "fuel-flow-gph" );
 174         net->EGT[i] = node->getDoubleValue( "egt-degf" );
 175         // cout << "egt = " << aero->EGT << endl;
 176         net->oil_temp[i] = node->getDoubleValue( "oil-temperature-degf" );
 177         net->oil_px[i] = node->getDoubleValue( "oil-pressure-psi" );
 178     }
 179
 180     // Consumables
 181     net->num_tanks = FGNetFDM::FG_MAX_TANKS;
 182     for ( i = 0; i < net->num_tanks; ++i ) {
 183         SGPropertyNode *node = fgGetNode("/consumables/fuel/tank", i, true);
 184         net->fuel_quantity[i] = node->getDoubleValue("level-gal_us");
 185     }
 186
 187     // Gear and flaps
 188     net->num_wheels = FGNetFDM::FG_MAX_WHEELS;
 189     for (i = 0; i < net->num_wheels; ++i ) {
 190         SGPropertyNode *node = fgGetNode("/gear/gear", i, true);
 191         net->wow[i] = node->getDoubleValue("wow");
 192         net->gear_pos[i] = node->getDoubleValue("position-norm");
 193         net->gear_steer[i] = node->getDoubleValue("steering-norm");
 194         net->gear_compression[i] = node->getDoubleValue("compression-norm");
 195     }
 196
 197     // the following really aren't used in this context
 198     net->cur_time = globals->get_time_params()->get_cur_time();
 199     net->warp = globals->get_warp();
 200     net->visibility = fgGetDouble("/environment/visibility-m");
 201
 202     // Control surface positions
 203     SGPropertyNode *node = fgGetNode("/surface-positions", true);
 204     net->elevator = node->getDoubleValue( "elevator-pos-norm" );
 205     net->elevator_trim_tab
 206         = node->getDoubleValue( "elevator-trim-tab-pos-norm" );
 207     net->flaps = node->getDoubleValue( "flap-pos-norm" );
 208     net->left_aileron = node->getDoubleValue( "left-aileron-pos-norm" );
 209     net->right_aileron = node->getDoubleValue( "right-aileron-pos-norm" );
 210     net->rudder = node->getDoubleValue( "rudder-pos-norm" );
 211     net->rudder = node->getDoubleValue( "nose-wheel-pos-norm" );
 212     net->speedbrake = node->getDoubleValue( "speedbrake-pos-norm" );
 213     net->spoilers = node->getDoubleValue( "spoilers-pos-norm" );
 214
 215     if ( net_byte_order ) {
 216         // Convert the net buffer to network format
 217         net->version = htonl(net->version);
 218
 219         htond(net->longitude);
 220         htond(net->latitude);
 221         htond(net->altitude);
 222         htonf(net->agl);
 223         htonf(net->phi);
 224         htonf(net->theta);
 225         htonf(net->psi);
 226         htonf(net->alpha);
 227         htonf(net->beta);
 228
 229         htonf(net->phidot);
 230         htonf(net->thetadot);
 231         htonf(net->psidot);
 232         htonf(net->vcas);
 233         htonf(net->climb_rate);
 234         htonf(net->v_north);
 235         htonf(net->v_east);
 236         htonf(net->v_down);
 237         htonf(net->v_wind_body_north);
 238         htonf(net->v_wind_body_east);
 239         htonf(net->v_wind_body_down);
 240
 241         htonf(net->A_X_pilot);
 242         htonf(net->A_Y_pilot);
 243         htonf(net->A_Z_pilot);
 244
 245         htonf(net->stall_warning);
 246         htonf(net->slip_deg);
 247
 248         for ( i = 0; i < net->num_engines; ++i ) {
 249             net->eng_state[i] = htonl(net->eng_state[i]);
 250             htonf(net->rpm[i]);
 251             htonf(net->fuel_flow[i]);
 252             htonf(net->EGT[i]);
 253             htonf(net->oil_temp[i]);
 254             htonf(net->oil_px[i]);
 255         }
 256         net->num_engines = htonl(net->num_engines);
 257
 258         for ( i = 0; i < net->num_tanks; ++i ) {
 259             htonf(net->fuel_quantity[i]);
 260         }
 261         net->num_tanks = htonl(net->num_tanks);
 262
 263         for ( i = 0; i < net->num_wheels; ++i ) {
 264             net->wow[i] = htonl(net->wow[i]);
 265             htonf(net->gear_pos[i]);
 266             htonf(net->gear_steer[i]);
 267             htonf(net->gear_compression[i]);
 268         }
 269         net->num_wheels = htonl(net->num_wheels);
 270
 271         net->cur_time = htonl( net->cur_time );
 272         net->warp = htonl( net->warp );
 273         htonf(net->visibility);
 274
 275         htonf(net->elevator);
 276         htonf(net->elevator_trim_tab);
 277         htonf(net->flaps);
 278         htonf(net->left_aileron);
 279         htonf(net->right_aileron);
 280         htonf(net->rudder);
 281         htonf(net->nose_wheel);
 282         htonf(net->speedbrake);
 283         htonf(net->spoilers);
 284     }
 285 }
 286
 287
 288 void FGNetFDM2Props( FGNetFDM *net, bool net_byte_order ) {
 289     int i;
 290
 291     if ( net_byte_order ) {
 292         // Convert to the net buffer from network format
 293         net->version = ntohl(net->version);
 294
 295         htond(net->longitude);
 296         htond(net->latitude);
 297         htond(net->altitude);
 298         htonf(net->agl);
 299         htonf(net->phi);
 300         htonf(net->theta);
 301         htonf(net->psi);
 302         htonf(net->alpha);
 303         htonf(net->beta);
 304
 305         htonf(net->phidot);
 306         htonf(net->thetadot);
 307         htonf(net->psidot);
 308         htonf(net->vcas);
 309         htonf(net->climb_rate);
 310         htonf(net->v_north);
 311         htonf(net->v_east);
 312         htonf(net->v_down);
 313         htonf(net->v_wind_body_north);
 314         htonf(net->v_wind_body_east);
 315         htonf(net->v_wind_body_down);
 316
 317         htonf(net->A_X_pilot);
 318         htonf(net->A_Y_pilot);
 319         htonf(net->A_Z_pilot);
 320
 321         htonf(net->stall_warning);
 322         htonf(net->slip_deg);
 323
 324         net->num_engines = htonl(net->num_engines);
 325         for ( i = 0; i < net->num_engines; ++i ) {
 326             net->eng_state[i] = htonl(net->eng_state[i]);
 327             htonf(net->rpm[i]);
 328             htonf(net->fuel_flow[i]);
 329             htonf(net->EGT[i]);
 330             htonf(net->oil_temp[i]);
 331             htonf(net->oil_px[i]);
 332         }
 333
 334         net->num_tanks = htonl(net->num_tanks);
 335         for ( i = 0; i < net->num_tanks; ++i ) {
 336             htonf(net->fuel_quantity[i]);
 337         }
 338
 339         net->num_wheels = htonl(net->num_wheels);
 340         for ( i = 0; i < net->num_wheels; ++i ) {
 341             net->wow[i] = htonl(net->wow[i]);
 342             htonf(net->gear_pos[i]);
 343             htonf(net->gear_steer[i]);
 344             htonf(net->gear_compression[i]);
 345         }
 346
 347         net->cur_time = ntohl(net->cur_time);
 348         net->warp = ntohl(net->warp);
 349         htonf(net->visibility);
 350
 351         htonf(net->elevator);
 352         htonf(net->elevator_trim_tab);
 353         htonf(net->flaps);
 354         htonf(net->left_aileron);
 355         htonf(net->right_aileron);
 356         htonf(net->rudder);
 357         htonf(net->nose_wheel);
 358         htonf(net->speedbrake);
 359         htonf(net->spoilers);
 360     }
 361
 362     if ( net->version == FG_NET_FDM_VERSION ) {
 363         // cout << "pos = " << net->longitude << " " << net->latitude << endl;
 364         // cout << "sea level rad = " << cur_fdm_state->get_Sea_level_radius()
 365         //      << endl;
 366         cur_fdm_state->_updateGeodeticPosition( net->latitude,
 367                                                 net->longitude,
 368                                                 net->altitude
 369                                                   * SG_METER_TO_FEET );
 370         if ( net->agl > -9000 ) {
 371             cur_fdm_state->_set_Altitude_AGL( net->agl * SG_METER_TO_FEET );
 372         } else {
 373             double agl_m
 374               = net->altitude - globals->get_scenery()->get_cur_elev();
 375             cur_fdm_state->_set_Altitude_AGL( agl_m * SG_METER_TO_FEET );
 376         }
 377         cur_fdm_state->_set_Euler_Angles( net->phi,
 378                                           net->theta,
 379                                           net->psi );
 380         cur_fdm_state->_set_Alpha( net->alpha );
 381         cur_fdm_state->_set_Beta( net->beta );
 382         cur_fdm_state->_set_Euler_Rates( net->phidot,
 383                                          net->thetadot,
 384                                          net->psidot );
 385         cur_fdm_state->_set_V_calibrated_kts( net->vcas );
 386         cur_fdm_state->_set_Climb_Rate( net->climb_rate );
 387         cur_fdm_state->_set_Velocities_Local( net->v_north,
 388                                               net->v_east,
 389                                               net->v_down );
 390         cur_fdm_state->_set_Velocities_Wind_Body( net->v_wind_body_north,
 391                                                   net->v_wind_body_east,
 392                                                   net->v_wind_body_down );
 393
 394         cur_fdm_state->_set_Accels_Pilot_Body( net->A_X_pilot,
 395                                                net->A_Y_pilot,
 396                                                net->A_Z_pilot );
 397
 398         fgSetDouble( "/sim/alarms/stall-warning", net->stall_warning );
 399         fgSetDouble( "/instrumentation/slip-skid-ball/indicated-slip-skid",
 400                      net->slip_deg );
 401         fgSetBool( "/instrumentation/slip-skid-ball/override", true );
 402
 403         for ( i = 0; i < net->num_engines; ++i ) {
 404             SGPropertyNode *node = fgGetNode( "engines/engine", i, true );
 405
 406             // node->setBoolValue("running", t->isRunning());
 407             // node->setBoolValue("cranking", t->isCranking());
 408
 409             // cout << net->eng_state[i] << endl;
 410             if ( net->eng_state[i] == 0 ) {
 411                 node->setBoolValue( "cranking", false );
 412                 node->setBoolValue( "running", false );
 413             } else if ( net->eng_state[i] == 1 ) {
 414                 node->setBoolValue( "cranking", true );
 415                 node->setBoolValue( "running", false );
 416             } else if ( net->eng_state[i] == 2 ) {
 417                 node->setBoolValue( "cranking", false );
 418                 node->setBoolValue( "running", true );
 419             }
 420
 421             node->setDoubleValue( "rpm", net->rpm[i] );
 422             node->setDoubleValue( "fuel-flow-gph", net->fuel_flow[i] );
 423             node->setDoubleValue( "egt-degf", net->EGT[i] );
 424             node->setDoubleValue( "oil-temperature-degf", net->oil_temp[i] );
 425             node->setDoubleValue( "oil-pressure-psi", net->oil_px[i] );
 426         }
 427
 428         for (i = 0; i < net->num_tanks; ++i ) {
 429             SGPropertyNode * node
 430                 = fgGetNode("/consumables/fuel/tank", i, true);
 431             node->setDoubleValue("level-gal_us", net->fuel_quantity[i] );
 432         }
 433
 434         for (i = 0; i < net->num_wheels; ++i ) {
 435             SGPropertyNode * node = fgGetNode("/gear/gear", i, true);
 436             node->setDoubleValue("wow", net->wow[i] );
 437             node->setDoubleValue("position-norm", net->gear_pos[i] );
 438             node->setDoubleValue("steering-norm", net->gear_steer[i] );
 439             node->setDoubleValue("compression-norm", net->gear_compression[i] );
 440         }
 441
 442         /* these are ignored for now  ... */
 443         /*
 444         if ( net->cur_time ) {
 445             fgSetLong("/sim/time/cur-time-override", net->cur_time);
 446         }
 447
 448         globals->set_warp( net->warp );
 449         last_warp = net->warp;
 450         */
 451
 452         SGPropertyNode *node = fgGetNode("/surface-positions", true);
 453         node->setDoubleValue("elevator-pos-norm", net->elevator);
 454         node->setDoubleValue("elevator-trim-tab-pos-norm",
 455                              net->elevator_trim_tab);
 456         node->setDoubleValue("flap-pos-norm", net->flaps);
 457         node->setDoubleValue("left-aileron-pos-norm", net->left_aileron);
 458         node->setDoubleValue("right-aileron-pos-norm", net->right_aileron);
 459         node->setDoubleValue("rudder-pos-norm", net->rudder);
 460         node->setDoubleValue("nose-wheel-pos-norm", net->nose_wheel);
 461         node->setDoubleValue("speedbrake-pos-norm", net->speedbrake);
 462         node->setDoubleValue("spoilers-pos-norm", net->spoilers);
 463     } else {
 464         SG_LOG( SG_IO, SG_ALERT,
 465                 "Error: version mismatch in FGNetFDM2Props()" );
 466         SG_LOG( SG_IO, SG_ALERT,
 467                 "\tread " << net->version << " need " << FG_NET_FDM_VERSION );
 468         SG_LOG( SG_IO, SG_ALERT,
 469                 "\tNeeds to upgrade net_fdm.hxx and recompile." );
 470     }
 471 }
 472
 473
 474 // process work for this port
 475 bool FGNativeFDM::process() {
 476     SGIOChannel *io = get_io_channel();
 477     int length = sizeof(buf);
 478
 479     if ( get_direction() == SG_IO_OUT ) {
 480         // cout << "size of cur_fdm_state = " << length << endl;
 481         FGProps2NetFDM( &buf );
 482         if ( ! io->write( (char *)(& buf), length ) ) {
 483             SG_LOG( SG_IO, SG_ALERT, "Error writing data." );
 484             return false;
 485         }
 486     } else if ( get_direction() == SG_IO_IN ) {
 487         if ( io->get_type() == sgFileType ) {
 488             if ( io->read( (char *)(& buf), length ) == length ) {
 489                 SG_LOG( SG_IO, SG_DEBUG, "Success reading data." );
 490                 FGNetFDM2Props( &buf );
 491             }
 492         } else {
 493             int result;
 494             result = io->read( (char *)(& buf), length );
 495             while ( result == length ) {
 496                 if ( result == length ) {
 497                     SG_LOG( SG_IO, SG_DEBUG, "  Success reading data." );
 498                     FGNetFDM2Props( &buf );
 499                 }
 500                 result = io->read( (char *)(& buf), length );
 501             }
 502         }
 503     }
 504
 505     return true;
 506 }
 507
 508
 509 // close the channel
 510 bool FGNativeFDM::close() {
 511     SGIOChannel *io = get_io_channel();
 512
 513     set_enabled( false );
 514
 515     if ( ! io->close() ) {
 516         return false;
 517     }
 518
 519     return true;
 520 }